pH meter



FIG. 1 is a perspective view thereof;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom thereof; and,

FIG. 6 is a right view thereof, the left side view being a mirror image thereof. 

The ornamental design for a pH meter, as shown and described. 